Are your food portions healthy?

Are your food portions healthy? (Jonathon Berlin and Rick Tuma)

It's tempting to read a silver lining into the otherwise dreary news that food prices are skyrocketing and appear on pace to post their largest annual increase since 1980.

Record high oil prices sent bicycle sales up 24 percent and gas-guzzling SUV sales down 35 percent in 2008, according to the U.S. Department of Transportation. High electric bills have prompted more than one of us to don a sweater rather than crank the heat. And increased cigarette taxes are credited with reducing teen smoking, according to at least one anti-tobacco group.

Sometimes, in other words, we need our wallets to be our willpower. So will rising food costs be the answer to our nation's notorious portion control issues?

No way, says renowned eating behavior researcher Brian Wansink, author of "Mindless Eating: Why We Eat More Than We Think" (Bantam). Affordability isn't what's driving us to overeat, he contends.

"The three biggest drivers that mess us up are: how big our portions are, how frequently we eat and what we eat," he says.

And none of those is likely to change significantly because of a spike in food prices.

"We spend about a fourth as much of our income on food as we did in 1960," say Wansink. "So it's no longer, 'Do I really want to sacrifice my entire allowance for a candy bar?' Now it's 'What else do I want too?'"

Even as the amount of money we spend on food has shrank, our portions have grown. Which speaks to another factor in our portion wars — the desire to save a buck.

"It's a long-standing principle in America that we're a land of plenty and we value bigness," says sociologist Barry Glassner, author of "The Gospel of Food: Why We Should Stop Worrying and Enjoy What We Eat" (Harper Perennial). "That's coupled with a very common American interpretation of what counts as value. Getting more for less is something that we tend to think is a good thing."

How else to explain the 44-ounce soda? No one's really that thirsty. But when the convenience store prices all fountain drinks at $0.79, what kind of sucker is going to reach for the smallest cup?

Rethinking need

Our reasons for overeating are as plentiful and varied as the folks doing the overeating. (And with a national obesity rate at around 34 percent, that's plenty of us.) But one commonality? A misunderstanding of how much food we actually need.

"If you look at the research, people grossly overestimate how much protein they need each day in order to grow. Same with grain and other categories," Wansink says. "We aren't really clear on the notion of normal servings and normal-size meals. We used to think a hamburger and small fry would fill us up. Now we believe we need a double cheeseburger, and anything less isn't going to do."

That double cheeseburger also takes a lot less effort to procure than it did a couple generations ago. So does a pizza. Or two. Frozen food, fast food and packaged food are all staples of modern life, but they allow us to scarf down massive portions without a lick of food prep.

Food also satisfies needs beyond just the need to quiet a grumbling stomach, of course.

"Our 'needs' for food go way beyond a strictly nutritional sense," says Glassner. "We have a lot of social aspects and psychological aspects at play, so to pretend it's just a simple nutritional issue is naive at best.

"Do I need a dessert, from a nutritional sense? No," he continues. "Do I need a dessert because it's the polite thing to have one when I'm a guest and people are offering it? Yeah, I need it. And I can think of a lot of examples like that."

So what can be done to reign it in?

Glorifying the eating habits of days past won't actually whip us into shape any more than rising food prices will.